1 // SPDX-License-Identifier: GPL-2.0-only
3 * regmap based generic GPIO driver
5 * Copyright 2020 Michael Walle <michael@walle.cc>
8 #include <linux/gpio/driver.h>
9 #include <linux/gpio/regmap.h>
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/regmap.h>
15 struct device *parent;
16 struct regmap *regmap;
17 struct gpio_chip gpio_chip;
21 unsigned int reg_dat_base;
22 unsigned int reg_set_base;
23 unsigned int reg_clr_base;
24 unsigned int reg_dir_in_base;
25 unsigned int reg_dir_out_base;
27 int (*reg_mask_xlate)(struct gpio_regmap *gpio, unsigned int base,
28 unsigned int offset, unsigned int *reg,
34 static unsigned int gpio_regmap_addr(unsigned int addr)
36 if (addr == GPIO_REGMAP_ADDR_ZERO)
42 static int gpio_regmap_simple_xlate(struct gpio_regmap *gpio,
43 unsigned int base, unsigned int offset,
44 unsigned int *reg, unsigned int *mask)
46 unsigned int line = offset % gpio->ngpio_per_reg;
47 unsigned int stride = offset / gpio->ngpio_per_reg;
49 *reg = base + stride * gpio->reg_stride;
55 static int gpio_regmap_get(struct gpio_chip *chip, unsigned int offset)
57 struct gpio_regmap *gpio = gpiochip_get_data(chip);
58 unsigned int base, val, reg, mask;
61 /* we might not have an output register if we are input only */
62 if (gpio->reg_dat_base)
63 base = gpio_regmap_addr(gpio->reg_dat_base);
65 base = gpio_regmap_addr(gpio->reg_set_base);
67 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
71 ret = regmap_read(gpio->regmap, reg, &val);
75 return !!(val & mask);
78 static void gpio_regmap_set(struct gpio_chip *chip, unsigned int offset,
81 struct gpio_regmap *gpio = gpiochip_get_data(chip);
82 unsigned int base = gpio_regmap_addr(gpio->reg_set_base);
83 unsigned int reg, mask;
85 gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
87 regmap_update_bits(gpio->regmap, reg, mask, mask);
89 regmap_update_bits(gpio->regmap, reg, mask, 0);
92 static void gpio_regmap_set_with_clear(struct gpio_chip *chip,
93 unsigned int offset, int val)
95 struct gpio_regmap *gpio = gpiochip_get_data(chip);
96 unsigned int base, reg, mask;
99 base = gpio_regmap_addr(gpio->reg_set_base);
101 base = gpio_regmap_addr(gpio->reg_clr_base);
103 gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
104 regmap_write(gpio->regmap, reg, mask);
107 static int gpio_regmap_get_direction(struct gpio_chip *chip,
110 struct gpio_regmap *gpio = gpiochip_get_data(chip);
111 unsigned int base, val, reg, mask;
114 if (gpio->reg_dir_out_base) {
115 base = gpio_regmap_addr(gpio->reg_dir_out_base);
117 } else if (gpio->reg_dir_in_base) {
118 base = gpio_regmap_addr(gpio->reg_dir_in_base);
124 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
128 ret = regmap_read(gpio->regmap, reg, &val);
132 if (!!(val & mask) ^ invert)
133 return GPIO_LINE_DIRECTION_OUT;
135 return GPIO_LINE_DIRECTION_IN;
138 static int gpio_regmap_set_direction(struct gpio_chip *chip,
139 unsigned int offset, bool output)
141 struct gpio_regmap *gpio = gpiochip_get_data(chip);
142 unsigned int base, val, reg, mask;
145 if (gpio->reg_dir_out_base) {
146 base = gpio_regmap_addr(gpio->reg_dir_out_base);
148 } else if (gpio->reg_dir_in_base) {
149 base = gpio_regmap_addr(gpio->reg_dir_in_base);
155 ret = gpio->reg_mask_xlate(gpio, base, offset, ®, &mask);
160 val = output ? 0 : mask;
162 val = output ? mask : 0;
164 return regmap_update_bits(gpio->regmap, reg, mask, val);
167 static int gpio_regmap_direction_input(struct gpio_chip *chip,
170 return gpio_regmap_set_direction(chip, offset, false);
173 static int gpio_regmap_direction_output(struct gpio_chip *chip,
174 unsigned int offset, int value)
176 gpio_regmap_set(chip, offset, value);
178 return gpio_regmap_set_direction(chip, offset, true);
181 void *gpio_regmap_get_drvdata(struct gpio_regmap *gpio)
183 return gpio->driver_data;
185 EXPORT_SYMBOL_GPL(gpio_regmap_get_drvdata);
188 * gpio_regmap_register() - Register a generic regmap GPIO controller
189 * @config: configuration for gpio_regmap
191 * Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
193 struct gpio_regmap *gpio_regmap_register(const struct gpio_regmap_config *config)
195 struct gpio_regmap *gpio;
196 struct gpio_chip *chip;
200 return ERR_PTR(-EINVAL);
203 return ERR_PTR(-EINVAL);
205 /* we need at least one */
206 if (!config->reg_dat_base && !config->reg_set_base)
207 return ERR_PTR(-EINVAL);
209 /* if we have a direction register we need both input and output */
210 if ((config->reg_dir_out_base || config->reg_dir_in_base) &&
211 (!config->reg_dat_base || !config->reg_set_base))
212 return ERR_PTR(-EINVAL);
214 /* we don't support having both registers simultaneously for now */
215 if (config->reg_dir_out_base && config->reg_dir_in_base)
216 return ERR_PTR(-EINVAL);
218 gpio = kzalloc(sizeof(*gpio), GFP_KERNEL);
220 return ERR_PTR(-ENOMEM);
222 gpio->parent = config->parent;
223 gpio->driver_data = config->drvdata;
224 gpio->regmap = config->regmap;
225 gpio->ngpio_per_reg = config->ngpio_per_reg;
226 gpio->reg_stride = config->reg_stride;
227 gpio->reg_mask_xlate = config->reg_mask_xlate;
228 gpio->reg_dat_base = config->reg_dat_base;
229 gpio->reg_set_base = config->reg_set_base;
230 gpio->reg_clr_base = config->reg_clr_base;
231 gpio->reg_dir_in_base = config->reg_dir_in_base;
232 gpio->reg_dir_out_base = config->reg_dir_out_base;
234 /* if not set, assume there is only one register */
235 if (!gpio->ngpio_per_reg)
236 gpio->ngpio_per_reg = config->ngpio;
238 /* if not set, assume they are consecutive */
239 if (!gpio->reg_stride)
240 gpio->reg_stride = 1;
242 if (!gpio->reg_mask_xlate)
243 gpio->reg_mask_xlate = gpio_regmap_simple_xlate;
245 chip = &gpio->gpio_chip;
246 chip->parent = config->parent;
248 chip->ngpio = config->ngpio;
249 chip->names = config->names;
250 chip->label = config->label ?: dev_name(config->parent);
252 #if defined(CONFIG_OF_GPIO)
253 /* gpiolib will use of_node of the parent if chip->of_node is NULL */
254 chip->of_node = to_of_node(config->fwnode);
255 #endif /* CONFIG_OF_GPIO */
258 * If our regmap is fast_io we should probably set can_sleep to false.
259 * Right now, the regmap doesn't save this property, nor is there any
260 * access function for it.
261 * The only regmap type which uses fast_io is regmap-mmio. For now,
262 * assume a safe default of true here.
264 chip->can_sleep = true;
266 chip->get = gpio_regmap_get;
267 if (gpio->reg_set_base && gpio->reg_clr_base)
268 chip->set = gpio_regmap_set_with_clear;
269 else if (gpio->reg_set_base)
270 chip->set = gpio_regmap_set;
272 if (gpio->reg_dir_in_base || gpio->reg_dir_out_base) {
273 chip->get_direction = gpio_regmap_get_direction;
274 chip->direction_input = gpio_regmap_direction_input;
275 chip->direction_output = gpio_regmap_direction_output;
278 ret = gpiochip_add_data(chip, gpio);
282 if (config->irq_domain) {
283 ret = gpiochip_irqchip_add_domain(chip, config->irq_domain);
285 goto err_remove_gpiochip;
291 gpiochip_remove(chip);
296 EXPORT_SYMBOL_GPL(gpio_regmap_register);
299 * gpio_regmap_unregister() - Unregister a generic regmap GPIO controller
300 * @gpio: gpio_regmap device to unregister
302 void gpio_regmap_unregister(struct gpio_regmap *gpio)
304 gpiochip_remove(&gpio->gpio_chip);
307 EXPORT_SYMBOL_GPL(gpio_regmap_unregister);
309 static void devm_gpio_regmap_unregister(void *res)
311 gpio_regmap_unregister(res);
315 * devm_gpio_regmap_register() - resource managed gpio_regmap_register()
316 * @dev: device that is registering this GPIO device
317 * @config: configuration for gpio_regmap
319 * Managed gpio_regmap_register(). For generic regmap GPIO device registered by
320 * this function, gpio_regmap_unregister() is automatically called on driver
321 * detach. See gpio_regmap_register() for more information.
323 * Return: A pointer to the registered gpio_regmap or ERR_PTR error value.
325 struct gpio_regmap *devm_gpio_regmap_register(struct device *dev,
326 const struct gpio_regmap_config *config)
328 struct gpio_regmap *gpio;
331 gpio = gpio_regmap_register(config);
336 ret = devm_add_action_or_reset(dev, devm_gpio_regmap_unregister, gpio);
342 EXPORT_SYMBOL_GPL(devm_gpio_regmap_register);
344 MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
345 MODULE_DESCRIPTION("GPIO generic regmap driver core");
346 MODULE_LICENSE("GPL");